This invention relates generally to spinning machines, such as a spinning frame, a twisting frame and the like, and, in particular, to an improved doffing and donning method and apparatus applicable to the spinning machine of the type which is adapted to apply empty bobbins, carried on a conveying means, to the spindle thereof, from which full bobbins have been doffed.
Conventional stationary doffing apparatuses, of the type where all the full bobbins on each side of the spinning machine or a group of full bobbins are doffed simultaneously, can be broadly classified into three groups. The first group of doffing apparatuses, which is hereinafter referred to as "a duel conveyer type", comprises two conveyers, one for the full end and one for the empty bobbins, respectively, the full bobbins doffed from the machine spindles being placed on the full bobbin conveyer and the empty bobbins on the conveyer therefor being fitted onto the spindles from which the full bobbins have been doffed. The second group of doffing apparatuses, which is hereinafter referred to as "a single conveyer type", comprises a single conveyer having a plurality of bobbin supporting pegs arranged thereon at intervals half of the spacing between the adjacent spindles. The full bobbins doffed from the spindles are disposed on the alternate pegs and thereafter the conveyer is moved a length corresponding to the interval between the adjacent pegs so that the empty bobbins disposed on the remaining pegs between the full bobbins can be transferred to their donning position. Finally, the doffing apparatuses falling in the third group, which is hereinafter referred to as "a temporary refuge type", comprise a single conveyer and a refuge support, either the full bobbins or the empty bobbins being temporarily placed on the refuge support on the way thereof from the spindles to the conveyer or vice versa.
However, these groups of conventional doffing apparatuses have disadvantages. That is, the duel conveyer type apparatus requires a larger installation space due to the employment of two conveyers. The single conveyer type apparatus can not accommodate large packages, because the interval between the adjacent pegs is half of the spacing between the adjacent spindles, and the doffing method as carried out by this apparatus includes an additional step of moving the conveyer a distance corresponding to the interval between the pegs. Thus, a long time is necessary for the bobbins to be doffed and donned. The temporary refuge type apparatus can produce large packages. However, this also requires an additional step of temporarily storing the full or empty bobbins on the refuge support, resulting in the same disadvantage as the single conveyer type apparatus. In addition, the temporary refuge type apparatus is complex in construction.
With respect to bobbin holders for holding the bobbins to enable the bobbins to travel therewith, it is required that in a case of the full bobbin the holder holds it positively without causing any damage to the yarn layer thereon and the apparatus must mount the bobbin on and demount the bobbin, from the spindle, the refuge support and the conveyer without fail. Thus, it is understood that the bobbin holder preferably comprises a positive holding member, or members which is forcedly operated for the positive holding and release of the bobbin.
It is accordingly a principal object of this invention to provide a method and apparatus for doffing and donning bobbins in a spinning machine, which allows production of large packages with a reduced number of operating steps and without necessitating a complex construction.
It is another object of this invention to provide a method and apparatus for doffing and donning bobbins in a spinning machine wherein the doffing and donning is carried out by using the same pitch of bobbin holders and conveyor pegs as the pitch of the spindles of the spinning machine.
According to the invention, the method and apparatus for doffing and donning bobbins employ a plurality of improved bobbin holders, each of which is designed to positively hold both a full bobbin and an empty bobbin at one time so that the doffing and donning can be effected with relatively low frequency of movement of the bobbin holder, thus reducing the complexities and reducing the time for the doffing and donning.
According to the doffing and donning method of the invention, in a spinning machine of the type wherein at least one row of spindles is arranged along the side thereof and empty bobbins are applied to the spindles to take up yarns thereon to thereby provide full bobbins, the removal of the full bobbins from the associated spindles is carried out by moving the corresponding bobbin holders, which at this stage hold the empty bobbins too. The holder with the full and empty bobbins is then moved to place only the full bobbin in a predetermined position on a conveyer extending along the spinning machine and thereafter the holder applies the empty bobbin to the corresponding spindle.
In one embodiment, in order to allow the bobbin holder to positively hold the empty and full bobbins simultaneously, the bobbin holder comprises a fluid operated holding member with upper and lower holding portions, and a generally hollow body having an access opening provided therein. The holding member is fluid operated and moved between a retracted and a projected position to adjust the effective diameter of the access opening. When the holding member is in the projected position, the holder can hold simultaneously both the full bobbin and the empty bobbin at the upper and lower portions of the holding member, respectively, and when the holding member is in the retracted position, the effective diameter of the access opening is made larger than the maximum diameter of the empty bobbin so that the empty bobbin held by the holding member at its lower holding portion is allowed to move down free of the holder.